The 1986 amendments to the Safe Drinking Water Act requires 99.99% inactivation of Giardia. Water treatment facilitates that utilize surface water will have to use ozone or chlorine dioxide to be cost effective in meeting the new regulations. The specific aims of this project are to eliminate chlorite ion and chlorate ion by-products when chlorine dioxide is used in drinking water treatment. These specific aims are: 1. Improved analytical methodology and instrumentation 2. Reduction of ClO2- and ClO3- by using sulfur dioxide chemistry 3. Tuning ClO2 generators for maximum chlorine dioxide production Novatek will develop analytical methods and instrumentation for the accurate determination of low level concentrations of chlorite ion and chlorate ion resulting from the generation and/or use of chlorine dioxide in the purification of drinking water. Novatek will also develop technology for the removal of chlorite ion from drinking water by using sulfur dioxide/sulfite ion - free chlorine chemistry. Finally, Novatek will develop the necessary expertise and service personnel such that it can routinely visit water treatment facilities in the United States and provide the above services by carrying out the appropriate chemical analyses, chlorine dioxide generator tuning and training in the new analytical instrumentation and methodology.